Graywater can be contaminated with organic matter, suspended solids or potentially pathogenic microorganisms. However, if appropriately collected and handled, graywater can be safely reused for flushing toilets and urinals as well as irrigating certain trees and plants. Reuse of graywater reduces the demand on other sources of water, such as potable water, surface water and groundwater.

Oregon recognizes three types of graywater

Type 1: Untreated graywater or graywater that has passed through a physical process to remove solids, fats, oils and grease.

Type 2: Graywater that has passed through some type of chemical or biological process, such as a wetland, to further reduce solids and organic matter.

Type 3: Type 2 graywater that is also disinfected.

How to obtain a graywater permit

A person seeking to reuse graywater must first obtain a permit from DEQ. Three different permits for graywater reuse and disposal systems are available.

A Tier 1 general permit is available for single-family residences and duplexes with up to four bedrooms that is connected to a sanitary system and generate less than 300 gallons per day of Type 1 graywater that is used solely for subsurface irrigation of landscape plants or compost. A person requesting coverage under the 2401 general permit must:

A Tier 2 general permit is available for any structure that generates less than 1,200 gallons of Type 1 or Type 2 graywater per day and is connected to a sanitary system. A person requesting coverage under the 2402 general permit must submit to DEQ for review a complete permit application, including:

DEQ will issue an individual permit for any system ineligible for coverage under a Tier 1 or Tier 2 general permit as well as to anyone not wanting coverage under a general permit. A person requesting coverage under a Tier 3 individual permit must submit to DEQ for review a complete permit application, including:

DEQ will review the material and develop an individual permit with site-specific conditions. Tier 3 permits are subject to a 30-day public comment period. The cost of an individual permit will vary based on the size and complexity of the graywater reuse and disposal system.

How to renew a graywater permit

The current general graywater permit is valid until May 1, 2027. If you wish to continue permit coverage beyond May 1, 2027 DEQ must receive a permit renewal application form by March 2, 2027. If DEQ receives a complete renewal application on time, the permit will remain current until DEQ issues a new permit.

Monitoring and annual reports

The owner or operator of a graywater reuse and disposal system must monitor the operation of the system. An annual report certifying that the system was operated in compliance with the permit must be submitted to DEQ as described in the permit.

Tier 1 General Permit (2401)

A person operating a graywater reuse and disposal system under a Tier 1 general permit (2401) is only required to submit an annual report to DEQ when the permit is renewed. However, an annual report may be submitted to DEQ in lieu of the $40 annual compliance fee. To waive the annual compliance fee, the annual report must be submitted to DEQ by January 15 using the DEQ report form.

Tier 2 General Permit (2402) and Tier 3 Individual Permit

A person operating a graywater reuse and disposal system under a Tier 2 general permit (2402) or a Tier 3 individual permit is required to submit an annual report to DEQ by January 15 certifying that the system was operated in compliance with conditions in the permit.

Regulations and other information

DEQ regulates graywater reuse and disposal systems under Oregon Administrative Rules Chapter 340, Division 53, which establishes a policy that encourages graywater reuse while protecting public health safety and welfare, public water supplies and waters of the state. These rules are based on recommendations from DEQ's Graywater Advisory Committee.

The rules define three types of graywater (Type 1, Type 2 and Type 3), based on level of treatment, and identify specific beneficial purposes, such as landscape irrigation, for each type of graywater. The rules also establish treatment and monitoring requirements, setbacks, access and exposure controls, and site management practices necessary to protect public health and the environment.